1. Technical Field
This invention relates generally to motorcycles equipped with a rear track and front skis to enable the motorcycle to travel in snow, and to conversion kits for such motorcycles.
2. Related Art
Snow vehicles having substantially the same upper frame structure as that of a motorcycle are know to the art to be equipped with an endless track mounted at the rear of the vehicle in place of the rear drive wheel, and a steering ski mounted at the front portion in place of the front wheel. Such a vehicle is disclosed, for example, in U.S. Pat. No. 5,474,146. In this case, the swing arm of the motorcycle is removed and replaced with a modified swing arm mounting an intermediate set of transfer sprockets which connect the drive hub of the endless track to the drive sprocket of the engine through two linking chains. Such modification and requirement for replacement of the swing arm adds considerable cost and complexity to the manufacture and operation of such snow vehicles. Further, the front ski is pivotal in only the fore and aft direction, and thus the skis roll with the vehicle to the right or left when the vehicle is tilted to one side or the other, such as when making aggressive, sharp turns as one would normally do when operating a conventional motorcycle with front and rear wheels. Such tilting of the motorcycle has the effect of rolling the front ski toward one edge or the other, causing the ski to come out of full contact with the ground, thus losing traction and control of steering.
It is an object of the present invention to simplify the manufacture and construction of such snow cycles and to improve their steering and handling performance.